Hollywood has utilized the Dutch angle for decades, frequently to represent disorientation or confusion. In funkier films, Dutch angles are often used in lieu of square compositions. You can use it for a dramatic purpose, or to just make your shots more interesting; either way, there's probably no easier special effect to achieve than the Dutch angle.
Here's how a Dutch angle works: tilt the camera. That's it. Slightly rotate the camera in any direction to create an out-of-parallel relationship between the plane of focus and the typical human viewing orientation. Essentially what you're doing is twisting the horizon until it runs at an angle to the bottom of the frame.
Often with a Dutch angle the "more is better" axiom applies. In Hollywood directors have been chastised for relying too heavily on this "gimmicky" film trick, but a single still image reads a lot differently in Dutch than an entire 90-minute movie does. In "more is better" terms, the point is to exaggerate the angle itself-not the quantity of times it is used.
The peak of a Dutch angle is presumably 45 degrees, because as you get all the way toward 90 degrees it becomes simply a rotated composition from horizontal to vertical, or vice versa. In reality a 45-degree angle is probably too disorienting for most Dutch angles. Something more subtle, in the neighborhood of a 15- to 25-degree tilt is usually plenty. Either way, the key is this: if you're deliberately using a Dutch angle, make it known. It doesn't mean you have to go wild, but at least make sure it's clearly not an error of composition. There's nothing worse than an almost perfectly aligned image made to look like sloppy craftsmanship because of a half-hearted attempt at a Dutch angle.
Pay attention to how often a Dutch angle is applied in pop culture too. Turn on the TV, especially reality TV. Dutch angles are often employed to keep shots from looking starched and stiff. Nothing could be simpler or more effective. Careers and cultural phenomena have been built on this simple little twisted view of the world.
So the next time you're faced with a subject that needs some heightened tension, or perhaps a shot that needs a little something extra to avoid being boring or blasÃ©, try a Dutch angle. With a little twist you'll find that your compositions can be infinitely more interesting in almost any circumstance.